Conventional wood pallets include a base layer and a cargo layer separated therefrom by support blocks. The cargo layer has end deck boards assembled on connector boards that run the full length or width of the pallet. The end deck boards are coupled through the connector boards to the support blocks to build the primary structure of the pallet. The end deck boards are also known as lead boards, and the connector boards are also known as stringer boards. The base layer has end deck boards coupled to the support blocks.
To move the wooden pallets with cargo thereon, the lifting members of material handling equipment, such as fork lift tines from a forklift, are inserted into the gaps between the base and cargo layers. If the forklift is not stopped in time, the forklift crashes into one of the end deck boards of the pallet. Impacts such as this weaken the pallet and greatly shorten the lifespan of the pallet, thereby causing the pallet to be repaired more frequently and/or removed from service before its anticipated life cycle has been reached.
One approach for improving the resilience to impacts from material handling equipment is disclosed in FR 26600283, which provides separate support elements made out of plastic that have notches formed therein to receive connector boards from the cargo layer. The connector boards are positioned edgewise.
Another approach is disclosed in GB 2080763 which provides a support element configured as an elongated block of low density cellular material, such as polystyrene. An upper surface of the support element includes a sheet of stiffening material, and a corresponding lower surface also includes a sheet of stiffening material. The sheets of stiffening material may be wood, for example. An adhesive or other bonding material may be used to secure the sheets of stiffening material to the support element.
Yet another approach is disclosed in GB 2265137 which provides a plastic pallet comprising three spaced apart support elements that are linked together by three base plank members. The base plank members are orthogonal to the support elements. Supported by the support elements is a plurality of beams. Each of the support elements is an elongated member having on its upper surface a series of upstanding ribs and on its lower surface three recesses integrally connected together by sections. The beams are positioned between the ribs and bridge the three support elements while the base plank members located in the recesses bridge the support elements. Each support element comprises a one-piece member composed of a plastic material. Each beam is a hollow extruded member. The base plank members are also hollow extruded members.
Even in view of the above-described pallets, there is still a need to lengthen the lifespan of a pallet by improving its resiliency to impacts from material handling equipment.